Floating mine structure



Sept. 23, 1958 J. MOIR 2,853,006

FLOATING MINE STRUCTURE Filed Sept. 21, 1956 2 Sheets-Sheet 1 IN V EN TOR.

JAMES L. Mon-1 BY RMWKRM Sept. 23, 1958 J. L. MOIR 2,853,906

FLOATING MINE STRUCTURE Filed Sept. 21, 1956 2 Sheets-Sheet 2 E INVENTOR. 9 James L. Mon

BY @mmm Qty United States Patent FLOATING MINE STRUCTURE James L. Moir, Marcellus, N. Y.

Application September 21, 1956, Serial No. 611,306

14 Claims. (11. 102-16 This invention relates generally to marine mines, and has special reference to a floating type mine which is particularly adapted for use against small craft although it need not necessarily be confined to such use.

Briefly stated, the mine to be described herein is a comparatively small mine which may be used in relatively shallow water adjacent a shore, in a river, or the like. The mine is adapted to float just at the surface of the water and is constructed in such a manner that it is very difiicult to detect thereby making it highly effective as a defensive weapon against small, shallow draft boats such as invading landing craft which might not be endangered by larger, anchored mines. In addition, the mine is provided with a very sensitive firing mechanism which further enhances its value as a small craft weapon.

Accordingly, in view of the foregoing, it may be stated that the broad objective of the present invention is to provide a marine mine which is particularly suited for use as a defensive weapon against small craft.

A more specific object of the invention is to provide a marine mine which is constructed so that the only visible portion thereof will appear to be of substantially the same color as that of the water in which the mine is positioned, regardless of the shade or hue of the water.

Another specific object of the invention is to provide a marine mine which is adapted to float just at the surface of the water and is provided with a surge preventing means which minimizes the possibility of the mine riding up onto the crest of a wave where it would most easily be detected and also prevents the mine from bobbing as high as it normally would when riding in a wave trough.

A further specific object of the invention is to provide a marine mine having an extremely sensitive firing mechanism which can be actuated by the water in which the mine is positioned after contact with another object in the water.

Another object of the invention is to provide a marine mine which is relatively small and compact, all projecting and depending parts of the mine being retractable within the confines of the mine body to facilitate storage and transportation.

'Still another object of the invention is to provide a marine mine which is relatively simple in construction and inexpensive to produce.

A still further object of the invention is to provide a marine mine which may be easily transported and planted by aircraft and submarines as well as by surface craft.

Other objects and advantages of the invention will become apparent from the following detailed description thereof read in conjunction with the accompanying drawings which illustrate a representative embodiment of the invention for the purpose of disclosure.

In the drawings:

Figure 1 is a side elevation of a marine mine embodying the invention;

Figure 2 is a vertical section taken substantially through the center of the mine shown in Figure .1;

Figure 3 is a fragmentary vertical section corresponding to Figure 2 showing one of the firing elements of the mine in retracted position;

Figure 4 is a simple wiring diagram showing the electrical circuit for the time;

Figure 5 is a fragmentary vertical section taken substantially through the center of a slightly modified form of the mine;

. assembly of Figure 8.

Having reference now to the drawings, wherein like reference numbers designate the same parts in each of the views, 10 generally indicates a typical mine embodying the invention wherein the mine is of relatively small size and is preferably formed with a substantially flat bottom 11, round side wall 12 and dome shaped top 14. The lower portion of the mine may be formed of metal or plastic and comprises a casing 15 enclosing an explosive chamber 17 which contains the explosive charge 18. The upper part of the mine, i. e. the dome shaped top, is formed of transparent material and includes a water chamber 20 and a sealed buoyancy chamber 21.

In accordance with the invention, the water chamber 20 is adapted to receive water from the body in which the mine is positioned for the purpose of imparting to the transparent dome shaped top of the mine a color which substantially matches that of the surrounding water, the top of the mine normally being the only portion of the .mine visible above the water at any time. Accordingly,

the dome shaped top 14 is formed of some material such as clear plastic or glass, Plexiglas being one such material having the requisite transparency and strength requirements.

The dome shaped top is secured to the explosive chamber casing 15 as by a threaded connection 22 and, as shown in Figure 2, the buoyancy chamber 21 is formed in the hollow wall thereof between an inner layer 24 and outer layer 25 of the transparent material. Air or other colorless gas is sealed within the buoyancy chamber so that the mine will float and, since it should float just below the surface of the water with only the transparent top thereof ever being visible, the volume of the chamber is determined with relation to the weight of the mine so that this condition will be satisfied.

The water chamber 20 of the mine occupies the space between the explosive chamber casing and the domed transparent wall, and the latter is formed with radial passages 27 extending therethrough to permit entrance into the chamber of the water. The passages 27 are sealed from the surrounding buoyancy chamber 21 and are defined by transverse marginal walls 28 which connect registering holes in transparent layers 24, 25. Since the water entering the chamber 20 is that of the body in which the mine is positioned, it will be understood that this water will impart to the transparent chamber wall, or give the wall the appearance of having, a color which is substantially the same as that of the surrounding water whether the latter be blue-green sea water, brownish river Water or water or any other shade or hue. The mine is thus very diflicult to detect by visual means.

The mine is provided with an electro-responsive detonator which is shown diagrammatically at 30 in Figures 2 and 4, and this detonator acts through the usual booster charge (not shown) to explode the main charge 18. To fire the detonator, a source of electric energy is provided in the form of a battery illustrated diagrammatically at 31. This battery can be in the form of a dry cell, or it can be a conventional sea cell with communication through the bottom of the mine with the sea water for activation. The circuit beitweenthe body 31 and the detonator is normally open by reason of a plurality of normallyopen switches 32 in parallel with one another as indicated in Figure 4. I

The switches 32 are respectively housed in a plurality of tubular firing elements 34, see Figure 6, and each comprises a pair of spaced, uninsulated leads or contacts 35. The tubular elements 34 are closed at both ends, and the insulated portion 36 of the leads passes through the inner ends thereof in water-tight relation thereto. Elements 34 are formed of-readily frangible material such as glass and are adapted to break upon impact and admit seawater which short circuits the contacts 35. Breakage of any one of the elements 34 and entrance of water there into thus closes one of the switches 32 causing the detonator to fire. To insure breakage upon even a slight im- I pact, .the elements 34 may be scored as at 37 adjacent their outer-ends to further weaken the frangible material thereof.

When the mine is positioned in the water, the tubular firing elements 34 project radially outwardly from the side wall 12 of the explosive chamber casing 15 so as to beflvulnerable, to impact from collision with another object in the water. However, before the mine is planted, it is preferable to have the firing elements in a retracted position to avoid the possibility of accidental breakage and to facilitate storage and transportation. To this end, the elements are slidably mounted in open ended tubes 38 which, extend radially inwardly into the explosive chamber 17 from the side wall of the casing. The ends of these tubes are turned inwardly as best shown at 40 in Figure 3, and these inwardly turned tube ends engage flanges 41 on the inner ends of the firing elements to prevent separation of the parts when the elements are in their outwardly projecting positions.

The firing elements 34 are held in their outwardly projecting positions by light compression springs 42 mounted in the inner ends of the tubes 38. When the elements 34 are in retracted position in the tubes, these springs are compressed as shown in Figure, 3, and the elements are held in this position against the spring bias by means of an .adhesively coated tape 44 which extends circumferentially around the side wall of the explosive chamber casing and blocks the open outer end of each of the tubes 38. The adhesive coating employed on this tape is water soluble so that when the mine is planted the tape will loosen and allow the springs 42 to project the firing elements into operative position. To avoid undue strain on the tape 44, it is contemplatedthat a thin band (not shown) of plastic or metal will be positioned thereover when the mine is in storage or being transported, this reinforcing band being manually removable from the mine just prior to planting.

Figure 5 illustrates a slightly modified form of the mine wherein the dome shaped top 14' is formed of but a single layer 24 of the transparent material, and the buoyancy chamber 21 is located below the water chamber 20 instead of within the wall of the top as shown in Figures 1 and 2. In this modification, therefore, the upper. portion of the water chamber 20' is enclosed by buta single thickness wall, the remainder of the mine structure being the same.

In order to prevent the mine from riding up onto the crests of the waves where it would most easily be detected, surge preventing means are provided comprising an elongated member 45 depending from the bottom of the mine and one or more Vane assemblies 47 hingedly secured to thismember. Member 45 is preferably a flexible cable but may also be in the form of a rigid rod if desired. Each vane assembly includes a pair of mating vanes 47a, 47b,

Figures 8 and 9 having registering elongated holes 48 through which the cable 45 passes with a loose fit, the assembly being held in fixed longitudinal position on the cable by means of tight fitting beads 50. The vanes 47a, 47b are formed with mutually underlying, interfitting offset lugs 51 which permit the vanes to assume an upwardly folded position but prevent downward folding beyond an extended, substantially horizontal position as shown in Figure 8.

In operation, when the mine starts to ride up onto the crest of the wave, the vanes 47a, 47b are moved to their extended, horizontal position by the resistance of the water and retard the upward surge of the mine. However, when the mine is riding down into the troughs between the waves, the resistance of the waterin the reverse direction causes the vanes to fold upwardly so that minimum resistance is offered thereby to the downward movement. This action causes the mine to travel just below the crests of the waves as'indicated by the dotted line 52 in Figure 7.

A Weight 54 of predetermined size may be secured to. i the lower extremity of the cable 45 to compensate for an.

over-buoyancy of the mine and aid in the proper positioning, thereof in the water. This Weight may also serve,in the event thatthe mine is washed too close to shore, to prevent a complete beaching thereof since the Weight will hit the bottom first and tend to hold the mine against further movement inshore. A recess 55 is formed in the bottom 11 of the mine for storage of the weight, vane assemblies and cable before the mine is planted, and these depending parts may be releasably held in the recess by a tape having a water soluble adhesive as above described.

The outer surface of the transparent dome shaped top 14 of the mine may be roughened or otherwise treated to diffuse light striking it and prevent direction refiection, and this can be accomplished without measurably effecting the transparency thereof. It should also be noted that other means for firing the mine, such as a mechanical means, may be employed without in any way efiecting the camouflaging feature or other features herein described' If desired, the mine can be provided with a conventional self-destroying mechanism and timer therefor.

From the foregoing description it Will be apparent that the invention provides a novel and highly effective floating mine structure having particular utility in shallow water areas against small craft and the like. The novel construction of the mine prevents easy detection by visual means and the sensitive firing mechanism thereof insures detonation upon even a slight impact.

sive to manufacture and may be easily stored, transported and planted.

The invention may be embodied in other specific forms without departing from the spirit or essential character.- isticsthereof. The embodiment disclosed is therefore to be considered in all respects as illustrative and not re.- strictive, the scope of the invention being indicated by the appended claims.

What is claimed is:

1.-In a floating mine, an explosive chamber, a buoyancy chamber, and a water chamber adapted to receive water from the body of water in which the mine is floating, said water chamber having a substantially transparent wall forming the only portion of the mine normally visible from above the water.

2. In a floating mine, an explosive chamber, a scaled buoyancy chamber, and a water chamber positioned above said explosive chamber and adapted to receive water from the body of water in which the mine is floating, said water chamber having a substantially transparent top wall forming the only portion of the mine which is normally visible from above the water whereby water water.

In addition tothese features, the mine is relatively simple and inexpen-' 3. In a floating mine, an explosive chamber, a sealed buoyancy chamber, a water chamber positioned on the upper side of said mine above said explosive chamber, said water chamber having a substantially transparent wall the upper portion of which is the only portion of the mine normally visible from above the water, and means in said wall to permit the entrance of water from the body of water in which the mine is floating into said water chamber to impart to said visible upper portion a color substantially matching that of the surrounding water.

4. Structure as defined in claim 3 wherein said buoyancy chamber is formed in said transparent water chamber wall.

5. Structure as defined in claim 3 wherein said buoyancy chamber is positioned below said water chamber.

6. In a floating mine, a chamber adapted to contain explosive material, a plurality of frangible elements projecting radially outwardly from the side wall of said chamber, means in each of said elements operable upon contact with the water in which the mine is floating to initiate detonation of the explosive material, a buoyancy chamber, and a water chamber having means to permit entrance into the chamber of water from the body of water in which the mine is floating, said water chamber having a substantially transparent wall forming the only portion of the mine normally visible from above the water.

7. In a marine mine, an explosive chamber forming the lower portion of the mine including top, bottom and side walls, a plurality of elongated frangible elements slidably mounted in the side wall of said chamber and adapted to project radially outwardly therefrom when the mine is in the water, means in each of said elements operable upon contact with the water in which the mine is positioned to initiate detonation of the explosive material, a water chamber forming the upper portion of the mine having a substantially transparent top wall, said top wall being the only portion of said mine normally visible above the water, said water chamber including means to permit free ingress thereinto of water from the body of water in which the mine is positioned whereby the water received in the chamber imparts to said transparent top wall a color substantially matching that of the surrounding water.

8. In a floating mine, an explosive chamber, a sealed buoyancy chamber containing entrapped air, a water chamber positioned on the upper side of said mine above said explosive chamber, said water chamber having a substantially transparent wall the upper portion of which is the only part of the mine normally visible above the water, said wall having apertures therethrough to permit free communication between the interior of the water chamber and the water in which the mine is floating whereby water entering the chamber imparts to said transparent wall a color substantially matching that of the surrounding water, a plurality of elongated frangible tubes slidably mounted in said mine, said tubes being confined within the mine when the latter is not in use and being adapted to project radially outwardly therefrom when the mine is in the water, means operable to move said tubes into their outwardly projecting positions, means to retain said tubes in their confined positions against the action of said moving means, said lastnamed means being releasable by action of the water in which the mine is positioned to enable said moving means to move said tubes into their outwardly projecting positions, an electro-responsive detonator in said explosive chamber, a source of electrical energy in said mine, a normally open switch in each of said tubes in circuit with said energy source and detonator, any one of said tubes in its outwardly projecting positions being breakable upon impact with other objects in the water to admit water thereinto and complete the circuit through its switch thereby initiating detonation of the explosive material.

9. Structure as defined in claim 8 wherein said buoyancy chamber is formed in said transparent water chamber wall.

10. Structure as defined in claim 8 wherein said buoyancy chamber is positioned below said water chamber.

11. In a floating mine, an explosive chamber, a sealed buoyancy chamber, a water chamber positioned on the upper side of said mine above said explosive chamber, said water chamber having a substantially transparent wall the upper portion of which is the only part of the mine normally visible above the water, means in said wall to permit the entrance of water from the body of water in which the mine is floating into said water chamber to impart to said visible upper portion a color substantially matching that of the surrounding water, and surge preventing means connected with said mine comprising a plurality of pairs of hinged vanes operable to enable downward movement of the mine into the troughs of the waves but retard upward movement of the mine to the crests of the waves.

12. Structure as defined in claim 11 wherein said surge preventing means includes a flexible cable depending from the bottom of the mine, said vanes being mounted on said cable and being hinged to permit movement only between an extended substantially horizontal position and an upwardly folded position.

13. Structure as defined in claim 11 wherein said mine is formed with a recess in the bottom thereof for storage of said surge preventing means when the mine is not in use.

14. In a marine mine, surge preventing means comprising an elongated flexible member depending from the lower portion of the mine, a pair of hinged vane members mounted on said flexible member, said vane mem bers being adapted to move between a confronting upwardly folded position and an extended substantially horizontal position, means on said vane members to prevent movement thereof into a downwardly folded position, and means to hold said vane members in fixed longitudinal position on said flexible members.

References Cited in the file of this patent UNITED STATES PATENTS 1,535,633 Sperry Apr. 28, 1925 FOREIGN PATENTS 308,132 Germany Oct. 1, 1918 11,153 Holland May 15, 1924 

